Grinding mill



N. NELSON GRINDING MILL April 7, 1931.

Filed March 26, 1928 3 Sheets-Sheet 1 Jba/a J7 April 7, 1931. NELSONGRINDING MILL Filed March 26, 1928 3 Sheets-Sheet 2 N. NELSON GRINDINGMILL April 7, 1931.

Filed March 26, 1928 3 Sheets-Sheet 5 72 1 762' j/JOT Patented Apr. .7,1931 UNiTED STATES PATENT; OFFICE NICOLAY NELSON, OF WAUKEGAN, ILLINOIS,ASSIGNOR TO BLATCHFORD CALI MEAL COMPANY, OF WA'UKEGAN, ILLINOISGRINDING MILL Application filed March 26, 1928. Serial No. 264,629.

This invention relates to mills for grinding grains, cereals,screenings, or other material which is adapted to be ground in IIllllSof the beater type.

5 The objects of this invention are to provide an improved mill whichwill be particularly eflicient in operation and which will require acomparatively small amount of power in proportion to its capacity; toprovide a mill having different types of heaters arranged to coact withgrinding surfaces; to provide a mill having fiat bar heaters andcombined hammer or T beaters; to provide a novel ar-' rangement formounting the heaters; to provide means for ventilation or circulation ofair throughout the interior of the .mill; to provide adjustable airinlets to facilitate the grinding operation and also to clean certamportions of the mill; to prpvide a centrifugal mill of comparativelylarge diameter whereby it will operate effectively at a relatively lowspeed; to provide readily removable screen guideways; and to providesuch other advantages-and novel features as will be described more fullyhereinafter.

In the accompanying drawings illustrat ing'this invention;

Figure 1 is a side view with parts omitted or shown diagrammatically forconvenience in illustration;

Figure 2 is a front view;

Figure 3 is an enlarged sectional side view taken on the line 3-3 ofFigure 2;

Figure 4 is a cross sectional view taken on the line 44 of Figure 3; and

Figure 5 is adiagrammatic view or pro: jection illustrating the spacingand arrangement of the beater elements.

In order to make the mill comparatively light, and also suflicientlystrong, I prefer to construct the body or casing of sheet steel andmount the same on a base formed of cast iron. As shown in the drawings,the base or bent plate 6 carries the casing which comprises a lowersection 7 and an upper section 8 which is provided with a cover 9. Themill is preferably provided with a double feeding arrangement 10 wherebythe material may be fed in at the outer periphery of the mill asindicated at 11 or through the sides as indicated at 12.

The bottom portion of the casing 7 is provided at either end with airintake open- 'ings 13 and 14 which are provided with adjustable slides15 and 16 for regulating the same. The upper portion 8 of the casing isprovided on either side adjacent to thecenter with one or more airintake openings 17 which are provided with adjustable covers 18 for relating the same.

he cover or upper portion of the mill is provided with any suitable formof grinding surface or devices, as for instance the stationary beaterbars or plates 19, as shown in Figure 3. The sides of the lower portionof the casing are provided with removable guide strips 20 having one ormore slots 21 for receiving the screen 22. These guides projectoutwardly at one end of the machine and a cover plate 23 is providedwhich is held in position by a bolt 24. This arrangement pro-' videsmeans whereby the screen may be quickly inserted or removed and may beadjusted with respect to the beaters. The latter provision is desirableas the grinding capacity for some materials is increased or decreased byhaving the screen plate nearer to or farther away from the beaters. Asthe grooves in the screen guides are apt to become worn, they may bereadily renewed by removing the guides and inserting new ones.

The heaters and mechanism which will now be described form one of theimportant parts of the present invention. The center shaft 25 which ismounted in suitable bearings (not shown) carries a hub 26 which is keyedor otherwise rigidly secured thereon. This hub 'ablyarranged on the hubin such manner that the openings through the various disks will be inalignment and will be in alignment with the holes through the flange 27.The disks'are held together and fastened to the flange 27 by bolts 31and spreaders 32 adj acent to the hub and are also further held by bolts33 and spreaders 34, which bolts pass through the outer edge of the.flange 27. The plates or disks 29 are provided around their outerperiphery with holes 35 for receiving rods 36 for supporting thebeaters. These rods may be conveniently held against longitudinalmovement by collars 37 and set screws 38 which are interposed betweenadjacent disks, as shown in Figure 4. While any suitable beaters ma beutilizdQI prefer to use a combination o grinding beaters 39 and barbeaters 40, as shown particularly in Figures 3 and 5. The grindingheaters 39 may be of the type shown in my prior Patent No. 1,492,102issued April 29, 1924, but in the present instance I provide sockets orholes 41 in the outer portions of the beaters forv receiving weights 42of lead or the like, whereby the beaters may be readily and accuratelybalanced. These beaters are usually formed of cast steel and are likelyto be of different weights and if they are not properly balanced are aptto set up undue strains in the machine on account of its high velocity.

The bar beaters 40 are carried on arms 43 which are pivoted on the rods36.

' The particular arrangement of the beaters in the mill, whichconstitutes another important feature, is shown diagrammatically inFigure 5. Starting at the left of the figure it will'be seen that thereare three grinding beaters 39 which are arranged in alignmenttransversely of the machine, all being mounted on one'of the rods 36. Asingle beater is mounted on the next rod and three beaters on thesucceeding rod. A bar beater is then arranged between these beaters, andthe next three beaters, and so on around the disks. I have found thatarticularly good results may be obtained y using four of the bar heatersand forty-four grinding beaters, arranged m the manner shown. The singlegrinding beaters are arranged on opposite sides, as indicated, so thateach group of or the side openings 12 and will be rapidly gri ng beaterswill practically cover the ent1re width of the mill, the single beaterscovering the spaces between the beaters of the ad acent series.

When the mill is in operation, the materiah will be drawnin through thefeed opening 11 ground and beaten by the action of the, rotatm'g membersin conjunctionwith the stationary elements and will be dischargedthrough the base which is provided with an'outlet 44. A suction fan maybe provided at the outlet if desired. During the grinding operation air'may be admitted through the holes 17 and on account of the highvelocity of the-rotatmg members, the air will be drawn in throu h theholes 30 in the disks and may also pass t rough the holes 28 in theflange 27 and will be equally disiributed throughout the easing. Thiswill facilitate the even distribution of the material across the entirewidth of the machine so that the grinding operation is performed in anequal manner by various elements throughout the machine, therebyproviding a uniform grinding action as well as preventing undue wear onany point of the machine. It will also be noted that the bar beaterswill tend to distribute the material across the inner face of the casingas well as tending to create a draft through the mill due to thecentrifugal action therein.

By opening the slides 15 and 16, air may be permitted to enter in thebottom of the casing, thereby tending to prevent the accumulation ofdust or feed in the bottom of the mill and also ending to keep thescreen clean.

As indicating'the relative proportions of the machine, the outsidediameter of the heaters is about forty inches and the machineapproximately 12 inches wide. On account of the comparatively largediameter this machine when run at the relatively low speed of eighteenhundred revolutions per minute will have a large capacity, and it may bedirectly driven by an electric motor, thereby avoiding the necessity ofbeing keyed or belted for increasing the speed.

It will of course be apparent that the arrangement of the heaters may bevaried for different materials and the proportions and.

construction of the machine may be modified for different purposes;therefore I do not wish to be limited to the exact arrangement hereinshown and described, except as specifled in the following claims, inwhich I claim:

1. In a device of the character set forth, the combination of a shaft, aplurality of disks carried by said shaft, grinding beaters mounted onsaid disks, and bar beaters mounted on the disks intermediate of thegrinding heaters.

2. In a grindin mill, the combination of a casing, a shaft t rough saidcasing, a plurality of disks mounted on said shaft, arms pivotallymounted on said disks, bars secured to the outer ends of the arms andextending substantially across the casing, and .grinding beaterspivotally mounted on the disks between the bar beaters, said grindingbeaters having serrated outer faces and substantially T-shaped in crosssection the head portions thereof extending only a portion of thedistance across the casing, substantially as described.

3.'A grinding mill having a rotor provided with a plurality of T-shapedgrinding heaters, and a plurality of bar beaters interposed betweensetsof the grinding beaters.

4. A rotating element for grinding mills having spaces around theperiphery thereof, a plurality of substantially T.-shaped hammerbeaters, and a plurality of bar beaters, said hammer beaters beingarranged in groups, some being in staggered relation with the others,and the bar beaters being arranged between the groups of hammer beaters.

5. The combination with a hub, of a plurality of disks secured thereto,rods extending through said disks, collars and set screws for holdingthe rods against longitudinal movement, and beaters pivotally mounted onsaid rods.

6. A grinding mill comprising a casing having a substantiallyrectangular bottom portion and a semi-circular upper portion, a

semi-circular screen mounted in the bottom portion, said upper portionbeing provided with internal grinding means, a shaft passing throughsaid casing, disks secured to said shaft and having passagestherethrough, beaters pivotally mounted on said disks, adjustable airopenings in said casing adjacent to the shaft and adapted to permit airto enter and pass through said disks, and adjustable air openings in thelower portion of the casing below the screen,

7. In a grinding mill, the combination of a casing, a shaft through saidcasing, adjustable air openings in the sides of the casing adjacent tothe shaft, a hub mounted on the shaft and extending substantially thefull width of the casing and having an outwardly extending flange withrelatively large openings therethrough to permit free circulation of theair, discs fitting closely over the hub and having relatively large airopenings which register with the openings in said flange, means forspacing the discs longitudinally of the hub, bolts passing throu h saiddiscs and flange and beaters carried by said'discs.

8. In a mill of the character set forth, the combination of a casing'havin a feed mlet adjacent to the periphe and aving a bottom discharge,a shaft t rough said casing, air intake openings in the side of thecasing ad acent to the shaft,.adjustable slides for said openings, a hubsecured to said shaft and having an outwardly projecting flange withentering through said openings to circulateair passageways therethrough,a plurality of discs fitting over said hub and having air passagestherethrough, means for securin the discs to the flange and heaterscarrie by said discs, said air 0 enings through the discs and flangebeing a apted to permit air freely to the center of the caslng.

9. In a grinding mill, a rotor comprising a shaft having a plurality ofspaced hammer supporting plates thereon, circumferentially spaced hammercar 'ng rods mounted in said plates, groups 0 hammers arranged oncertain of said rods, stirrup hammers mounted on other rods and arrangedbetweer groups of the first mentioned hammers, eacl of said stirruphammers spanning a pluralit j of the hammer supporting plates.

NICOLAY NELSON.

